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The construction of the well Z-2/1 in the Vinogradi well field, Osijek : master's thesis
No full textZdenac Z-2/1 je izveden na crpilištu Vinogradi, koje funkcionira u sklopu vodoopskrbnog sustava grada Osijeka, kao zamjenski zdenac za raniji zdenac koji se urušio tijekom revitalizacije. Hidrogeološke radove, koji su započeti 25. rujna 2023. te dovršeni 9. listopada 2023. izvodio je Vodovod Osijek. Ovim radom se opisuju relevantne značajke područja crpilišta i postupak izvedbe zdenca te se prikazuje izračun parametara vodonosnika i zdenca temeljen na podacima dobivenim iz pokusnog crpljenja u sklopu izvedbe zdenca te ranijih istraživanja.The well Z-2/1 is located at the Vinogradi well field, which operates as a part of the water supply system of the city of Osijek, serving as a replacement well for an earlier one that collapsed during the revitalization. Hydrogeological works, initiated on September 25, 2023, and completed on October 9, 2023, were carried out by Vodovod Osijek. This work describes the relevant features of the well field area and the well construction process, and presents the calculation of aquifer and well parameters based on data obtained from the well pumping test conducted during the well construction, as well as from earlier investigations
Geological modeling of a tectonically controlled hydrothermal system in the southwestern part of the Pannonian basin (Croatia)
No full textGeothermal energy is an important resource in the green economy transition. For the preservation of a geothermal resource it is crucial to assess its renewability and the sustainability of the exploitation. These aspects are influenced by the interaction among the physical, chemical, geological, and hydrogeological processes. The reconstruction of the geological assemblage allows the detailing of the geometries of the reservoir and fracture systems that influence the fluid flow and the water/rock interaction. The control of regional/local scale fault and fold systems on the development of the Daruvar hydrothermal system (DHS), located in Croatian part of the Pannonian basin, is detailed in this work. Field investigations were conducted to collect structural data on strata orientation and fault/fracture systems. The dataset was integrated with geological and geophysical data to develop composite geological profiles and a 3D geological model. Results display a pattern of generally N-S and E-W striking folds and cogenetic fracture systems with orientations parallel to the fold axes. The geological reconstruction was integrated with geophysical, hydrogeological, and geochemical data to propose a conceptual model of the DHS. The DHS is a topographically driven system hosted in a Mesozoic carbonate reservoir where E-W striking fracture systems are regional flow paths that enable infiltration of meteoric water to 1 km depth and its reheating in its reservoir area. In Daruvar, an anticline and fault/fracture systems accommodate the uplift of reservoir to shallow depths, promoting the bedrock fracturing and increase of the permeability field. These conditions favor the localized upwelling of thermal water resulting in four thermal springs (38°C and 50°C) in Daruvar city area. This work highlights the importance of employing a multidisciplinary approach to detail the complex interaction among the processes driving the geothermal resource
Lady’s mantle flower as a biodegradable plant-based corrosion inhibitor for CO2 carbon steel corrosion
No full textDue to issues with the corrosion problem in the petroleum industry and the use of less ecologically acceptable corrosion inhibitors, great emphasis, within research on corrosion inhibitors, is now being put on green corrosion inhibitors (GCIs). In this study, Lady’s mantle flower extract (LMFE) has been observed as a plant-based GCI for carbon steel in a simulated CO2-saturated brine solution. The effectiveness of the inhibitor in static and flow conditions has been determined using potentiodynamic polarization with Tafel extrapolation and electrochemical impedance spectroscopy (EIS). In static conditions, the inhibitor has been tested at concentrations from 1 g/L to 5 g/L with an increment of 1 g/L per measurement, while, in dynamic (flow) conditions, the inhibitor has been tested at concentrations from 3 g/L to 6 g/L with an increment of 1 g/L per measurement. All measurements were performed at room temperature. EIS and potentiodynamic polarization methods showed that LMFE achieves maximum effectiveness in protecting carbon steel from corrosion when added at a concentration of 4 g/L in static conditions and at a concentration of 5 g/L in flow conditions. The test methods proved that the inhibitory effectiveness of LMFE is greater than 90% in both test conditions (static and flow). The inhibitor efficiency was attributed to the adsorption of LMFE on the carbon steel surface, which was demonstrated by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). A biodegradability of 0.96 and a toxicity of 19.34% for LMFE were determined. The conducted laboratory tests indicate that LMFE could be used as an effective corrosion inhibitor for CO2 carbon steel corrosion
Utjecaj materijala obloge na detonacijske parametre ANFO eksploziva
No full textDue to the low manufacturing cost and ease of handling, ammonium nitrate-fuel oil (ANFO) is one of the most popular mining explosives. ANFO explosive is a typical representative of non-ideal explosives, which means that its detonation properties are strongly dependent on the charge diameter and the existence and properties of the confinement. In this work, the effect of different confining materials on the detonation properties of ANFO explosive is studied experimentally, and by hydrocode simulation by varying charge diameter, and the type and thickness of the confining materials. The results show that, along with the diameter of the charge, density and thickness of the confining material have a key impact on the detonation properties. An empirical confinement model, applicable in the range 0.3 < mC/mE < 15, is proposed. The model enables the estimation of detonation velocity of confined ANFO charges with a mean absolute percentage error (MAPE) of 14.25%.S obzirom na dobru učinkovitost miniranja, sigurnost i cijenu, ANFO eksploziv najčešće je korišteni eksploziv za civilnu primjenu. ANFO eksploziv tipičan je predstavnik neidealnih eksploziva, što znači da njegova detonacijska svojstva jako ovise o promjeru punjenja te postojanju i svojstvima obloge. U radu se eksperimentalno i simulacijom pomoću hidrokoda proučava utjecaj različitih materijala obloge na detonacijska svojstva ANFO eksploziva mijenjanjem promjera naboja te vrste i debljine obloge. Rezultati pokazuju da uz promjer naboja ključan utjecaj na detonacijska svojstva imaju gustoća i debljina materijala obloge. Predložen je empirijski model obloge, primjenjiv u rasponu od 0,3 < mC/mE < 15. Model omogućuje procjenu brzine detonacije ANFO naboja s oblogom od različitih materijala sa srednjom apsolutnom postotnom pogreškom (MAPE) od 14,25 %
Hydrogeological parameterisation of the Daruvar thermal aquifer: integration of fracture network analysis and well testing
No full textHighly fractured Mesozoic carbonate rocks are the main reservoir of many geothermal resources in northern Croatia, being of environmental, cultural, and economic value for the local and regional communities. The Daruvar thermal springs (temperatures < 50°C) represent the outflow area of an intermediate scale, tectonically controlled, hydrothermal system hosted in Triassic carbonate rocks. Several investigations have been conducted in the Daruvar area detailing the architecture of regional and local fracture networks and quantifying the hydrogeological parameters of the thermal aquifer. In this work, an integrated approach based on structural and hydrogeological investigations was employed to model the network of fractures in the reservoir and quantify its impact on the hydraulic properties. Structural investigations were conducted in the Batinjska Rijeka quarry, considered as an outcrop analogue of the thermal aquifer, employing both a classical field approach and the virtual quantitative analysis of a 3D digital outcrop model. Structural analysis of the digital outcrop model allowed identification of two sub-vertical systems of discontinuities, dipping to the NW and the WSW respectively, in accordance with the data collected through direct field measurements. The main geometric features of the discontinuity network and their statistical distributions were employed to construct discrete fracture network models at both the outcrop scale (approximately 100 m) and the aquifer scale in Daruvar (approximately 700 m). Calibration of the input parameters allowed modelling of porosity and permeability values that reproduce the field values assessed through pumping tests, well tests, and well logging. This work highlights the importance of integrating geological and hydrogeological investigations to obtain a more reliable reconstruction and quantification of the processes driving the fluid flow in fractured aquifers and affecting the spatial distribution of their hydraulic properties
Geochemistry and petrography of metamorphic sole amphibolites from the Slatina quarry, Mt. Zrinska Gora, Croatia
No full textThe investigated Mt. Zrinska Gora amphibolites are a part of the metamorphic sole of the Banovina ophiolite complex. Mineral composition and other petrographic characteristics of amphibolites and adjacent peridotite were investigated by polarised microscopy and chemical analyses of rocks were obtained by a combination of inductively coupled plasma mass and emission spectrometry. The main minerals in these garnet-bearing amphibolites are amphibole and plagioclase with accessory garnet, sphene, spinel, opaque mineral ± clinopyroxene ± quartz ± actinolite ± zoisite-clinozoisite ± prehnite ± pumpelyite and ± clay minerals. Kelyphitic corona is developed around garnet. The amphibolites have nematoblastic, nematogranoblastic, porphyroblastic and porphyroclastic textures and homogenous to foliated structures. The presence of clinopyroxene in some of the investigated amphibolites points to their possible formation under P‒T conditions of upper amphibolite facies. The greenschist facies retrograde metamorphism and subsequent surface weathering of amphibolites is also evident. The chemical composition of rocks indicates that protoliths of most amphibolites were tholeiitic basalts, initially formed in island arcs and the adjoining back-arc basins. During the intraoceanic subduction in Jurassic Neotethys Ocean basalts/basaltic tuffs of island arc tholeiite affinity and back-arc basin basalts, positioned on the top of the down-going oceanic slab, were welded to the base of the hot over-riding mantle wedge, metamorphosed to amphibolite rocks and obducted together with ophiolites on the Adria continental margine. The new described amphibolite type having peridotite protolith characteristics originated as the consequence of the hydration of the bottom part of the overlying mantle wedge
On some properties of a complete quadrangle
No full textIn this paper, we study the properties of a complete quadrangle in the Euclidean plane. The proofs are based on using rectangular coordinates symmetrically on four vertices and four parameters a,b,c,d. Here, many properties of the complete quadrangle known from earlier research are proved using the same method, and some new results are given
Parametric study of stability in landfills due to changes in waste composition
No full textThe modern trend in waste management in most developed countries in Europe and the world is based on waste reduction, reuse and recycling, while landfilling is considered the least desirable method in the waste management process. Despite this trend, landfilling is still the leading method of waste disposal in most countries. Considering the increasing amount of waste, even if all methods to reduce the amount of waste are used, there will still be a need to build a landfill. Waste is a heterogeneous material whose physical, mechanical and chemical properties are highly dependent on the composition of the waste, so even minor changes in composition can affect the change in these properties. In Croatia, in the process of approaching European Union standards, the composition of disposed waste has changed significantly, primarily due to the fact that biowaste, plastic waste and paper are increasingly separated from total municipal waste. The separation of these constituents significantly affects the density, moisture and granulometric composition of the deposited waste, which in turn affects the stability and deformations of the landfill body itself, as well as the stability of the protective layer system. In this work, the effects of changes in the physical and mechanical parameters of the landfilled municipal waste on the stability of the landfill body were analyzed
Dechipering of the pedo-sedimentary complex of Eastern Adriatic coast: a case study in Privlaka, Croatia
No full textThis study provides the first results of the Quaternary eight-meter-thick pedo-sedimentary complex developed in Privlaka, Croatia to understand the succession of paleosols and sediments, the deposition mechanism and the source of the material. This pedo-sedimentary profile (8 meters) is divided into four main units (Figure 1): a reddish paleosol and three sediment packages (sands with gravels) each indicating a different pedo-sedimentological context. Each distinctive horizon was sampled for sedimentological, physico-chemical, mineralogical and petrographical analyses to conduct a high-resolution investigation. In addition, optically stimulated luminescence (OSL) dating is used to assess the sediment’s age. Grain size analysis revealed that the paleosols are rich in finegrained components, predominantly silt. The quartz grains exhibit an angular to subangular morphology typical for (glacio-)fluvial transport, suggesting that the sand-gravel body is formed by sediment transport and deposition by water. The upper part of investigated profile has dominantly carbonate grains such as carbonate concretions (ryzoconcretions) and nodules. The CaCO3 content (calcites) generally decreases from the upper to the lower part of the investigated profile. All analysed samples had an alkaline reaction. Organic matter is higher in the paleosol part of the profile due to soil pedogenetic development. The proportion of the light mineral fraction (LMF) in almost all samples is roughly 98 %, with quartz as the dominant component, followed by lithic particles (5 – 15 %) and feldspars (3 - 7 %). Volcanic glass is accessory (<3 %). Such high content of quartz, suggesting that these sediments have undergone more redeposition of quartz than in loess of the northern Adriatic Island of Susak . The increase in weathered quartz grains with increasing depth could indicate that the proportion of fluvial sediments has increased compared to the aeolian sediments. The distribution of weight share for heavy mineral fraction (HMF) is uniform across the profile and ranges from 1.1 to 2.5 %. Among the HMF, opaque grains predominate. Along with opaque grains that cannot be determined (30 - 57 %), goethite grains make up a significant proportion (12 – 33 %). The most abundant transparent heavy minerals are resistant grains like dominant garnet (27 – 51 %), followed by zircon (9 – 24 %) and rutile (6 – 21 %). The predominant minerals in the paleosols are calcite and quartz. The samples also contain feldspars, goethite and some phyllosilicates. Two types of calcites are distinguished in the paleosol and (glacio-)fluvial sediments: primary calcite, which was formed by the process of physical weathering of carbonate rocks from the hinterland, and secondary, i.e., authigenic calcite, which was precipitated as a cement in carbonate concretions and rhyzoconcretions during pedogenesis. Petrographic analyses confirmed the presence of chromite, serpentinite and serpentinized olivine basalt, indicating the area of origin within ultramafic rocks, which could be the Dinaric ophiolitic zone in the hinterland. The carbonate grains are polygenetic in origin and consist of equal parts of highly spherical upper Cretaceous rudist limestones, Eocene nummulitic limestones and low spherical pedogenic carbonate concretions, indicating local transport. The apparent OSL ages of the (glacio-)fluvial sediment overlying the paleosol would range between ca. 230 ka and 130 ka for the lowermost sample, and ca. 190 ka and 105 ka for the uppermost sample. According to the OSL dating results, the (glacio-)fluvial materials were deposited during the earliest part of OIS5 or OIS6, while the paleosol can most likely not be younger than OIS5 and might even have an age that corresponds with OIS7. This research is funded by the Croatian Science Foundation under the project ACCENT (IP-2020-02-3274)
Final discussion and closing
No full textOnline workshop Western Istrian Anticline as an Ideal Natural Laboratory for the Study of the Regional Unconformities in Carbonate Rocks, Friday, April 12, 2024